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Ontario, Canada.

Calcium everything you were afraid to ask


Blossom-end splitting is not caused by a parasitic organism but is a physiologic disorder associated with a low concentration of calcium in the fruit. Calcium is required in relatively large concentrations for normal cell growth. When a rapidly growing fruit is deprived of necessary calcium, the tissues break down, leaving the characteristic dry, lesion at the blossom end. Blossom-end splis are induced when demand for calcium exceeds supply. Even with an abundance of calcium in the soil, inadequate calcium levels in the fruit can occur. This may also result from low calcium levels or high amounts of competitive cations in the soil(HIGH OM), drought stress, or excessive soil moisture fluctuations which reduce uptake and movement of calcium into the plant. Soil moisture content plays a critical role in the movement of calcium in soil and its uptake by roots. Without sufficient soil moisture, calcium will not move to the roots. If the soil is too wet, oxygen is unavailable for root growth and calcium will not be absorbed. Calcium is absorbed only by young root tips in which the cell walls of the epidermis are unsuberized. Once a suberin layer develops in these cells, water and calcium can no longer be absorbed. Suberin is a waxy substance through which water and nutrients cannot move. Excess soil moisture and a lack of oxygen results in the development of this suberin layer.

Rapid, vegetative growth due to excessive ammoniacal nitrogen fertilization. will cause fruit splits.

10/7/2005 5:02:38 PM

Ontario, Canada.

Foliar applications of calcium, which are often advocated, are of little value because of poor absorption and movement to fruit where it is needed. calcium does not move from leaves to the fruits. Thus, foliar sprays of calcium won't correct blossom end Splits. Pumpkin fruits do not have openings in the epidermis (skin) through which calcium can be absorbed. Contrary to past belief the direct application of calcium as a spray or towel, is ineffective.

Use nitrate nitrogen as the fertilizer nitrogen source. Ammonia-cal nitrogen may increase blossom end splits as excess ammonium ions reduce calcium uptake. Avoid over-fertilization as side dressings during early fruiting, especially with ammonia-cal forms of nitrogen.

Avoid drought stress and wide fluctuations in soil moisture by using mulches and/or irrigation. Even a brief soil water deficit can disrupt water and nutrient flow in the plant. If this occurs while fruits are developing, blossom-end splits will likely develop. Plants generally need about one inch of moisture per week from rain or irrigation for proper growth and development. If the irrigation of any kind is available, it should be used during periods of hot, drying winds. Start to irrigate at the beginning of the dry spell.

Mulching, which serves to maintain an even level of soil moisture, should be practiced where feasible.

10/7/2005 5:03:00 PM

Ontario, Canada.

Calcium Nitrate or calcium supplemented with a soluble N source high it nitrate should be used in small quantities at 1/4 strength or less at more frequent intervals. Applied to the soil & roots by drip irrigation.

Grow a backup secondary fruit(sink) just in case you prune to heavily or the beneficial bacteria kick into gear the hidden OM cations and provide a sudden surge of nuterients.

Slow down sudden respiration by shading the plant or misting at frequent intervals on hot days.

Always keep an area of the plant growing as a source of young unsuberized roots.

Drip irrigation of Phosporus(p) can be used to supplement availability to the roots.

10/7/2005 5:18:53 PM

Appalachian Mtns.

OK, gotta ask...where did this calcium info come from and can it be substantiated by scientific case studies?
(not that I think you're wrong Russ, just want to see it backed up before I go for it...especially the part that calcium can't be absorbed thru the pumpkin walls, or leaves, when I've seen info in the past to the contrary...at least I'm pretty sure someone posted a link to collegiate study)

10/7/2005 6:23:40 PM

Western NY

he's onto something, but there's more to some of those points. this will be a great thread to refer back to in about a month when i release all of my info from this year.

10/7/2005 9:04:09 PM

Paradise Mountain, New York

At the Oswego Weigh-off there was a Mr. Scott Lee from Agri-Tech. I asked him many different questions as he thoughts and in puts about atlantic Giants as far as growing them. He said, calcium does not move from the leaves to the pumpkin from foliage spraying. Also he said that lots of growers are applying calcium to the pumpkin by soaking sheets in calcium and then laying them on the pumpkin. which is said does very little or if not no good at all. Mr. Lee said that the calcium that is in the soil is the most important and the soil "has" to be all in balance for everything to work for the roots to supply it to the pumpkin.

10/7/2005 9:21:45 PM

Ontario, Canada.

Kyle, all of this stuff is in print. I have been digging for awhile. The unsuberized roots problem was revealed last fall in some of our disscussions then. Andy's, data and home work have suddenly provided what could be a possible solution. There are many more intriguing points that are burried inside many of the points above. Make no mistake, there is no cure for the common cold that the AGP seams to get at about day 30. But however, I now believe it is far more controllable that previously thought.

Drs. Hodges and Steinegger, Extension Specialists with the University of Nebraska, Lincoln, report calcium does not move from leaves to the fruits. Thus, foliar sprays of calcium won't correct blossom end rot. Tomato fruits do not have openings in the epidermis (skin) through which calcium can be absorbed. Contrary to past belief the direct application of calcium as a spray, based on information from Hodges and Steinegger, is ineffective.


http://www.coopext.colostate.edu/TRA/PLANTS/index.html#http://www.colostate.edu/Depts/CoopExt/TRA/PLANTS/mycorrhiza.html

10/7/2005 10:30:48 PM

Ontario, Canada.

I thought I had this problem resolved last fall but like any soil problem it always becomes far more complex then imagined. IMO, we are the cause of most of the splitting problems today. Genetics may play only a very minor roll. More investigation needs to be done to determine the interactions of cations in High OM soils with slightly acidic to moderate alkaline soils. I have a good idea on what is happening but the proof is still out there. My hope is that a discovery may point to a link that can be related to demonstrate this.

10/7/2005 10:44:52 PM

Puyallup, WA

I will "ditto" the notion that spraying calcium does little, if anything, to reduce splits. Do let me know when you can come up with a "split proof" growing method.

Stan
Puyallup, WA "Split Capital of the World"

10/7/2005 11:00:22 PM

Ontario, Canada.

I have got to get to bed. I'm taking a trip to the Niagara weigh off in the morning. Thanks Stan. Andy, maybe very close. That 1407 of his was a monster.

10/7/2005 11:19:12 PM

Appalachian Mtns.

Fair enough Russ. Looking forward to hearing more.

10/8/2005 7:41:14 AM

Ontario, Canada.

Kyle, nothing is written in stone. I am always open for discussion on these topics.

Acceptance of Calcium absorption by foliar is still controversial. I have read some studies that show it is effective on fruit trees. AGRO-K promotes the Vigor-cal solution. That is pretty hard to argue with all of the monster fruit in Ohio, Penn & NY using the Lembke program.

The Ca towel technique is pretty much a dead issue. It may in fact be doing more harm than good by trapping in ripening gases.

10/8/2005 4:45:48 PM

Ohio

I know one thing,if you have stock in liquid calcium,,,,SELL,SELL,SELL!

10/12/2005 10:47:22 PM

Appalachian Mtns.

I would think calcium drenches would be beneficial, all others variables being conducive?

10/14/2005 7:20:57 AM

Appalachian Mtns.

soil drenches that is...

10/14/2005 7:21:19 AM